


Cause and Effect

by deathtoonormalcy



Category: Free!
Genre: Anal Sex, Finger Sucking, Fingerfucking, Jealous!Rin, Jealousy, M/M, Possessive Behavior, Rough Sex, Shameless Smut, Virgin!Nitori
Language: English
Status: Completed
Published: 2013-08-23
Updated: 2013-08-23
Packaged: 2017-12-24 09:37:10
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 2,842
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/938414
Author URL: https://archiveofourown.org/users/deathtoonormalcy/pseuds/deathtoonormalcy
Summary: <blockquote class="userstuff">
              <p>Rin catches Haru and Makoto doing some extra training in the locker room. He decides that it's affected Haru's performance and Nitori volunteers to prove his theory wrong. Smutty Smut Smut.</p>
            </blockquote>





	Cause and Effect

"Do you want to go get something to eat? I'm starving?" Nitori yawned, tired from the hours of training he and Rin had just finished. Staying late at the large pool long after everyone had gone.

"Where do you want to go?" Rin asked, in one of his rare moods where he wasn't being as quiet as usual. He relaxed when it was just the two of them. Nitori liked to think he was the one who calmed down the older restless boy. He was the one Rin clung to when he needed something to bring him back to reality. He had so much anger bottled up inside, and Nitori knew how to soothe him.

They'd been rooming together for two years now, and a careful hand on Rin's back after nightmares was always welcomed with a small exhale and Rin leaning back into his palm.

"How about that ramen shop down the stre-" Nitori's voice stopped when he bumped into Rin's broad back. Scowling, he looked up at the taller boy.

"What?" He asked, watching his body tense in a way that only happened around Haru.

Sure enough Haru was there in the locker room. He was straddling the narrow wooden bench, and Nitori could see his erection leaking on the hard wood. Leaning low over his back was Makoto.

Haru's eyes raised and met Rin's.

Nitori choked on a gasp. Makoto hadn't yet realized that they'd been seen. He still roughly slammed his strong hips into Haru's pliant body. Haru gaped, about to warn him when Makoto did a particularly sharp thrust that had Haru craning forward and revealing the dark bruises lining his throat.

"So tight, Haru." Makoto grunted, placing a kiss on Haru's shoulder in an intimate display way that should never be seen by intruders. Nitori stumbled back. Rin stared, eyes wide and pained. Nitori could barely make out his profile.

" _Rin_." Nitori hissed, feeling his cheeks burn. Makoto must have heard because he looked up. Haru still hadn't told his love, and even when Makoto's strong rolling thrusts ceased, Haru kept rocking back wantonly. It made Nitori's face burn.

He had never seen someone so shameless.

In the dim locker room he could see the pink rim of Haru's rim, stretched and puckered over Makoto's slender cock. Haru's licked his swollen lips, and they looked glazed and sweet.

"Do you need something? We're busy." Haru finally spoke, everyone else frozen. He must have done something with his body, because Makoto was shuttering, doubling over and giving a half aborted thrust back into Haru's hole.

Rin made a disgusted noise.

"Fags!" He spat, turning and storming down the hallway. Nitori hesitated before following him.

"Sorry." He peeped.

* * *

Nitori watched Rin tear their room to shreds. Throwing a fit as he swiped the books from the desk along with the carefully organized pens and pencils. He ripped all their clothes from the closet, throwing them all over the room.

Nitori watched quietly from the little nest of his bed on the top bunk.

"Fucking queer! No wonder he can't win me in a race when he's letting the big idiot do that stuff to him!" Rin snarls, punching the wall. Nitori winches as his fist breaks threw. He has to distract him before he does it again.

"Why are you so upset?" Nitori asks carefully.

"My win didn't count, he's handicapped, he's  _impaired_! He just had a whole dick up his ass! No wonder he can't swim properly!" Rin rants. Nitori sees blood trickling from his fists. He comes down from his bunk and gets the first aid at the bottom of their desk. He gently takes Rin's fist and tries not to smile when he relaxes slightly.

"You can still swim properly, even after doing that sort of stuff." Nitori admits sheepishly. Wrapping Rin's fist in bandages. Rin goes tense, and Nitori almost checks over his shoulder to see if Haru had snuck into their room.

"You make it sound like you speak from experience." Rin scowls. Nitori looks up at him in shock before flushing and focusing on finishing the bandage. He yelps as Rin hauls him up by the front of his shirt.

"You let someone touch you?" Rin's eyes flash dangerously, and he isn't screaming. Is voice is low and dangerously even.

"N-No!" Nitori shouts, embarrassed and squirming as the older larger boy pins him to their desk.

"Don't lie to me, Nitori." Rin hisses. Nitori pushes at his strong hands before swallowing thickly.

"I-I'm not. No ones touched me." Nitori frowns, sliding his hands to Rin's forearms. He traces a pulsing vein with his finger, and Rin doesn't notice.

"Then how would you know if someone could swim after having something up their ass?" Rin's vulgar tongue makes him flinch. Nitori had never heard anyone speak like that until Rin became his roommate. He came from a wholesome family, and he was sheltered and a good student. He had been terrified of Rin when they'd first met.

The much taller, much broader boy had been lounging on the bottom bunk when he'd entered. He had heard rumors of him getting into a lot of fights and ditching classes. He had quiet the reputation. But after a few days they had formed an unlikely bond after Rin had nearly killed the bullies who had been harassing Nitori since his first week at their school.

"I ... I touched myself." Nitori's admits, shame making his cheeks red. He had done it only a few nights ago. Fingers slick, and pushed deep inside as he watched Rin sleeping below, soft snores echoing around the room.

Rin jerks back hard, his grip on Nitori's shirt slackening.

"With your fingers?" Rin's brow is furrowed, but his voice has lowered. Nitori hesitated before nodding.

"That's disgusting." Rin spits, shoving him hard against the desk. Nitori is used to being shoved around by Rin, but he winces hard and tries not to cry as he slinks up to his bed and falls into a fitful sleep.

* * *

Rin had avoided him for three days. Leaving earlier in the morning, and training all night. Nitori had gone about as usual. But Rin calling him  _disgusting_  hurt so much.

He wasn't an idiot. He knew Rin wasn't gay. Rin sometimes brought home pretty girls who he fucked into the mattress only a few feet below Nitori's own bed.

He could hear the heavy slap of Rin's balls slapping, and the heady smell of sex.

But he never complained. He tried not to get jealous over how much Rin obsessed over Haru. How he had been so mad after catching Haru getting bent over by Makoto.

Nitori knew Rin wasn't gay, and even if he was he wouldn't want anything to do with Nitori's himself.

But that didn't stop him from loving Rin.

At first it had been misplaced hero worship. Rin was his sempai after all, and it was hard not to care for Rin after he stood up for Nitori. One time telling a bully that 'The only one who gets to make Nitori's cry is me.' He had reveled in the way that out of the entire school he was the only one who Rin cared about. Who Rin would even speak too. Girls where jealous, and boys stopped making fun of Nitori for being 'cute'.

Nitori had jerked off the first time Rin brought home a girl. But not to the sound of the girl. To the soft grunts, and occasional smothered groans Rin would make.

It was then that Nitori realized he loved him.

It had only gotten worse. Nitori had stolen a pair of briefs that Rin had tossed in the hamper after jogging, they had been damp with his sweat. Nitori had pressed his face into them, inhaling the deep musk and coming all over himself.

He had lied and said Rin had a girlfriend when a very pretty girl had asked Nitori to give her love confession to him.

Nitori made sure to distract Rin if Haru was around. To whine and cling, until Rin became exasperated and started yelling at him.

Anything to get Rin's attention.

But now Rin was ignoring him and he felt like he wanted to die. If Rin react this badly from finding out Nitori was gay, then if he knew that the object of his fantasies was laying three feet below him every night he would surely ask to change rooms.

* * *

"Hey." Nitori groaned, rolling over to make room on his bed. Sometimes Rin got nightmares and liked to sleep with him. It was second nature now for him to scoot over and make room for the large teenager.

Rin settled against his back. Nitori was still half asleep to realize the significance of what was happening.

"Nitti, hey Nitti. Show me." Rin's voice seeped into his sleep fogged brain. The nickname 'Nitti' was one Rin had only used a few times, during some real emotional nights when they had shared a lot with each other about their pasts.

" _Nitori_." Rin pressed, hand sliding around his waist. Nitori whined, trying to squirm away.

"M'sleeping."

"Show me." Rin continued, pulling up the blankets and going underneath. Nitori sighed at the extra warmth pressed against his back. Rin was much too large to share a bed comfortably and they were piled on stop of each other.

"Show you what?" Nitori whimpered, trying to burrow under the pillow. Rin dragged him back against his chest and Nitori whimpered.

"Show me what you do with your fingers." Rin's voice was low and promising. The voice he used when he was seducing pretty girls in the bed below. Convincing them that it was okay that they just met him, he really liked them and of course he would call them tomorrow. Nitori was always relieved that Rin was lying to them.

"Wha?" Nitori rolled over, peeking over the blankets to see Rin's eyes half lidded and impatient.

"You said you could still swim even after having something up your ass. Prove it. Want you to show me." Rin said, bossily yanking at the blankets and reaching for Nitori's pajama pants. Nitori gasped, squeezing his thighs shut when Rin touched his hip.

"Y-You can't be serious." Nitori raked in a shaky breath. Rin yanked down his pants in one sharp movement. His half hard cock sprung up and he cried out in humilation, trying to cover it up. Rin ignored him, rolling him over.

"Here, show me." Rin snapped open some lube, gripping his hand and drizzled it over Nitori's fingers. Nitori swallowed, throat clicking dryly.

He hesitated, before slowing moving his hand behind him. He carefully pressed a finger to his hole, circling around it to loose it before gently pressing in. His hips rocked forward.

"Need more." Nitori mumbled into the pillow. Rin inhaled sharply, before dripping some more lube onto his hole. Nitori groaned into the pillow, sinking his finger in down to the first digit. It was so much better while knowing Rin was watching. He could feel his heavy gaze on his back. He could heard his labored breath.

Nitori gasped, hips stuttering when Rin grabbed his ass cheek and pulled it apart.

"Couldn't see." Rin grunted, thumb close enough to Nitori's hole that he whined in desperation.

He slowly started working his finger in and out, pushing it down until he could feel the webbing between his fingers.

Rin was so close that Nitori could feel his breath on the wetness of his skin.

"Put in another." Rin demanded. Nitori nodded, shaking as he slowly sunk in his second finger. His eyelashes fluttered, breath going choppy. Quickly he added the third, moaning around the stretch.

"Whore, you love it don't you." Rin grunted. Nitori jolted at his words, thrusting against his sheets as he nodded into the pillow.

"S'good. S'full, Rin." Nitori gasped, mewling as Rin's grip on his ass tightened pulling his ass further apart.

"It's no good." Rin's voice suddenly snapped, the authority it held made Nitori wilt. Humiliation washed over him like a tidal wave.

"You're fingers are too skinny, they're like a girls." Rin commented. Nitori was about to protest when he felt Rin trace a finger over Nitori's still stretched hole.

"I'm gonna have to do it." Rin pulled Nitori's hand away, holding it above his head. Single handedly he squirted on some more lube before pressing in with a long square digit.

"Uh! Ugh! Rin!" Nitori cried, twisted his hand to curl their fingers together. Rin snorted and released him, reaching down to spread his ass while using his other to spear open his hole.

"You're so hot inside." Rin said almost speculatively. Nitori let out a high pitched wail, hips trembling against the bed before he fucked back against Rin's finger.

"You like it that much? Does it feel good?" Rin asked, sounding mildly curious.

"So good, more. More inside." Nitori choked, trying to muffle his noises into the pillow when Rin quickly added another long finger in. Rin was right, Nitori's fingers weren't as big or long.

Rin pushed in deep, so deep that Nitori had never felt the white hot flashes going off behind his eyes.

" _Rin. Rin. Rin._ " Nitori murmured his name, wanting to drown in it. He'd never felt so strongly.

"You need another." Rin's voice was rough, gravelly like he had a cold. Nitori keened as a third finger was forced in. Rin shoved them in all the way, brushing something inside Nitori that made him freeze in shock before thrusting back like a slut to try and get Rin to touch it again. Rin was rough, sharp quick movement with his fingers that made Nitori fall apart.

"More, another, more." Nitori sobbed, clawing at the comforter. Rin pulled his fingers away completely and Nitori nearly swallowed his tongue.

"If you're not completely filled up, it's no good." Rin's breath was quick, like he's just swam a 500. He laid across Nitori's back, pushing his thighs together before spreading his ass to reveal his hole. Nitori whined, trembling under him.

Rin pushed in, and Nitori screamed into the pillow.

"Shut up, someone will hear." Rin growled, slipping a filthy hand over Nitori's mouth. Nitori whimpered as Rin forced his dirty fingers into his mouth. He drooled helplessly on them, sucking loosely as Rin sunk into his hole all the way. It burned, and he felt like he was being split in half.

But as soon as Rin pulled out and slammed back in, he hit that spot that made Nitori scream.

Nitori nipped at Rin's fingers, feeling the drag of Rin's hard cock going in and out of his wet hole. Rin removed his fingers from Nitori's mouth, gripping his hips tightly as he pounded into him.

"You're so wet." Rin rasped, pressing his face into Nitori's neck and nipping at his sweaty skin. Rin smelled like sex and chlorine, it was intoxicating. His sharp teeth scraped over Nitori's neck, leaving little welts that he hoped the other boys on their swim team noticed.

"Harder." Nitori hissed, and groaned as Rin fucked him. Rin licked at his spine, sucking a bruise possessively into his ribs. Nitori tried to keep his voice down, but every time he cried out Rin's hips would falter in their sharp brutal movements and jab at his prostate.

Rin dragged his hips up off the bed, forcing him to bare his ass into the night air.

Nitori was about to complain when Rin was stuffed back in him.

"Ohhh!" Nitori groaned, his upper half collapsing back onto the bed. He hugged the pillow, shaking apart at the new angle that made him feel more vulnerable.

With every one of Rin's thrusts, he could hear the slap of skin on skin, could hear the nasty squelch of his hole being fucked open and raw.

"I-I'm gonna-" Nitori choked, clinging to the pillow. Rin grinded down hard into his prostate, pressing in close to his ear as he nibbled on his lobe.

"Do it, _cum_." Rin ordered. Nitori gasped, tossing his head back as Rin dug his sharp teeth into Nitori's neck.

A few more jerky thrusts and Rin was coming inside Nitori, his cock swelling before gushing inside him hot and wet.

Rin collapsed on his back, breathing hard.

He rolled off, dragging Nitori onto his chest.

"We'll have you swim tomorrow, see if your time is the same." Rin says as soon as he gets his voice back.

Nitori frowns, hesitating before answering.

"Well Makoto probably does it a lot with Haru, it might affect him more." Nitori blushes as he lays a hand over Rin's racing heart. Rin glares up at the ceiling.

"I hadn't thought of that." He admits.

"We'll have to do it a lot, and see how my swimming is affected." Nitori mumbles, looking up at Rin hopefully.

Rin glances at him, before setting his jaw.

"Fine." He mutters shyly. Nitori smiles widely and curls up against him before falling asleep.


End file.
